'72 horsepower question
Thread Starter
Racer
Joined: Dec 2005
Posts: 492
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From: NJ
'72 horsepower question
I've read it explained a few different ways...the base 350 in '72 was rated at 200HP net. If this same engine was in a previous model, with the old gross HP calculations, would the performance be the same as the base 300HP? I've read that a 1971 330HP Lt-1 for instance rated at 330HP gross had the same performance as the '72 454 rated at 255HP net.
This is my reasoning (albeit most likely poor reasoning) for my assumption/hope that the 200HP net HP 1972 car is about the same performance as the previous 300 gross HP cars.
If anyone can chime in with experiences in cars running the base 1972 200HP engine it would be great. Not that I want to run it hard at all, but there is something about being able to say the HP is there if you want it.
I've also heard on many occassions that the 1972 started the "cruiser" era for corvette which leads me to believe the 'punch' isn't there.
This is my reasoning (albeit most likely poor reasoning) for my assumption/hope that the 200HP net HP 1972 car is about the same performance as the previous 300 gross HP cars.
If anyone can chime in with experiences in cars running the base 1972 200HP engine it would be great. Not that I want to run it hard at all, but there is something about being able to say the HP is there if you want it.
I've also heard on many occassions that the 1972 started the "cruiser" era for corvette which leads me to believe the 'punch' isn't there.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
Don't hold me to it ... but I think chevy's major change began MY1971. I target MY1971 as baseline for my assumptions for similar chevy motors produced since. Base 350 (L48) in MY1971 rated at 270hp. MY1971 L48 had dished pistons, 76cc heads, 390"/410 lift" cam.
Drifting
Joined: Aug 2003
Posts: 1,327
Likes: 16
From: Fl
1972 has PLENTY of get-up-and-go.
I have driven a 71' 454 car and compared it to my 72'. Not a bit of a difference. 71' --> 72', just the NET to SAE change (365 --> 270).
Both cars pull equally as fast.
Now having said all that - there is NO comparison to a 70' 454 or the 69' BB cars. They are friggin REALLY fast.
As stated above, 71' was the begining of the emission engines, they just got really bad in 75'.
I do not think you will be dissapointed with a 71' or 72' car. At least you can get the darn things to run on pump gas.
Bill
I have driven a 71' 454 car and compared it to my 72'. Not a bit of a difference. 71' --> 72', just the NET to SAE change (365 --> 270).
Both cars pull equally as fast.
Now having said all that - there is NO comparison to a 70' 454 or the 69' BB cars. They are friggin REALLY fast.
As stated above, 71' was the begining of the emission engines, they just got really bad in 75'.
I do not think you will be dissapointed with a 71' or 72' car. At least you can get the darn things to run on pump gas.
Bill
Pro
Joined: Apr 2005
Posts: 666
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From: Mt. Pleasant SC
Here's why your assumption is incorrect. In 71 the Society of Automotive Engineers started phasing in the new standards from SAE Gross HP to SAE Net HP. Both methods are measured at the flywheel; however, Gross HP is minus all the crap (fuel pump, alt, starter, emission controls, etc). Net HP is approximately 80% the value of Gross HP. With that in mind, your base small-block 350 in 72 rated at 200 net HP would be 250 gross HP, and not the 300 you had hoped for. To further complicate it, rear-wheel HP (RHP) is approximately 15% less then SAE Net for manual tranny and 20% less then SAE Net for auto tranny.
Hope that helped.
Hope that helped.
Thread Starter
Racer
Joined: Dec 2005
Posts: 492
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From: NJ
Originally Posted by c3andc5
Here's why your assumption is incorrect. In 71 the Society of Automotive Engineers started phasing in the new standards from SAE Gross HP to SAE Net HP. Both methods are measured at the flywheel; however, Gross HP is minus all the crap (fuel pump, alt, starter, emission controls, etc). Net HP is approximately 80% the value of Gross HP. With that in mind, your base small-block 350 in 72 rated at 200 net HP would be 250 gross HP, and not the 300 you had hoped for. To further complicate it, rear-wheel HP (RHP) is approximately 15% less then SAE Net for manual tranny and 20% less then SAE Net for auto tranny.
Hope that helped.
Hope that helped.
More first hand experiences welcomed (70-71 vs. 72).
I'm also considering a real nice '69 with the 350/300hp. will this feel head and shoulders faster than the '72 base?
Team Owner
Joined: Jun 2000
Posts: 38,923
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From: Southbound
Cruise-In II Veteran
Originally Posted by TSAGG
.....i just don't want it to feel like i'm driving a Ford Taurus if I buy a 72 base engine model.....
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Burning Brakes
Joined: Mar 2004
Posts: 923
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From: Austin Tx
Originally Posted by TSAGG
great info, thanks. i just don't want it to feel like i'm driving a Ford Taurus if I buy a 72 base engine model. After all, as a cruiser, the look is what matters most, but still want some grunt out of the engine.
More first hand experiences welcomed (70-71 vs. 72).
I'm also considering a real nice '69 with the 350/300hp. will this feel head and shoulders faster than the '72 base?
More first hand experiences welcomed (70-71 vs. 72).
I'm also considering a real nice '69 with the 350/300hp. will this feel head and shoulders faster than the '72 base?
Team Owner
Joined: Jul 1999
Posts: 26,545
Likes: 46
From: Huntersville NC
The only way to tell is to take the car to the drag strip, or a dyno.
Those base engine vettes turn in some pretty slow times at the strip, so that 200 net hp is the same 200 net hp I have in my Lexus ES300 and the seat of the pants and actual acceleration are likely similar. This is why people modify their cars.
Those base engine vettes turn in some pretty slow times at the strip, so that 200 net hp is the same 200 net hp I have in my Lexus ES300 and the seat of the pants and actual acceleration are likely similar. This is why people modify their cars.
Melting Slicks
Joined: May 2005
Posts: 2,152
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From: Folsom Ca
71 and 72 engines were the same the only difference was the way they were rated.Im guessing that a base 71 engine {270HP} would be the same as the base 72 engine {200HP}.
Compression dropped after 1970 so there`s a bigger difference between 70-71 than 71-72.
Compression dropped after 1970 so there`s a bigger difference between 70-71 than 71-72.
Thread Starter
Racer
Joined: Dec 2005
Posts: 492
Likes: 31
From: NJ
Originally Posted by PRNDL
The only way to tell is to take the car to the drag strip, or a dyno.
Those base engine vettes turn in some pretty slow times at the strip, so that 200 net hp is the same 200 net hp I have in my Lexus ES300 and the seat of the pants and actual acceleration are likely similar. This is why people modify their cars.
Those base engine vettes turn in some pretty slow times at the strip, so that 200 net hp is the same 200 net hp I have in my Lexus ES300 and the seat of the pants and actual acceleration are likely similar. This is why people modify their cars.
Basically, does the '72 base low HP engine hurt value?
Burning Brakes
Joined: Mar 2004
Posts: 923
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From: Austin Tx
Originally Posted by TSAGG
well, should I expect to pay less for a base '72 than a '69 with 300HP? (considering quality of cars are same)
Basically, does the '72 base low HP engine hurt value?
Basically, does the '72 base low HP engine hurt value?
Generally 69s are worth more than 72s all things being equal. You can easily mod the 72 base motor to 350 hp or more without changing the external appearance so it will look stock. If you want originality and neck snapping power, look for 70 or older
Pro
Joined: Apr 2005
Posts: 666
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From: Mt. Pleasant SC
Originally Posted by Gage
Generally 69s are worth more than 72s all things being equal. You can easily mod the 72 base motor to 350 hp or more without changing the external appearance so it will look stock. If you want originality and neck snapping power, look for 70 or older
Drifting
Joined: Dec 2004
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Originally Posted by 8T Shark
71 and 72 engines were the same the only difference was the way they were rated.Im guessing that a base 71 engine {270HP} would be the same as the base 72 engine {200HP}.
Compression dropped after 1970 so there`s a bigger difference between 70-71 than 71-72.
Compression dropped after 1970 so there`s a bigger difference between 70-71 than 71-72.
In 1971 GM quoted BOTH net and gross HP numbers as follows in their brochures:
270 Gross / 210 Net for the base 350, 330 Gross / 275 Net for the LT-1 350, 365 Gross / 285 Net for the LS-5 454, and 425 Gross / 325 Net for the LS-6 454.
In 1972 the net ratings dropped across the board to:
200 Net for the base 350, 255 Net for the LT-1 350, and 275 Net for the LS-5 454.
The additional loss was due to tightening emmissions levels.
There is NO debate, just look at an original 1971 sales brochure.
Drifting
Joined: Dec 2004
Posts: 1,345
Likes: 3
Originally Posted by lps&vettes
I wouldn't get too excited about 10 horsepower looking at it from a performance aspect. It's highly unlikely you would ever notice the difference.
Instructor
Joined: Dec 2005
Posts: 246
Likes: 1
From: Concord NC
I have a '72 LT-1 and with all this conversation being said...I think the car is a blast to drive. It is incredible how it starts to really pull at about 3 grand on the tac and keeps right on gettin' it until my heart starts pounding at about 4500. I have had some Corvette Club members here in North Carolina tell me the fun STARTS at about 4500 with the LT-1 models. I can't imagine what an older model LT-1 must have been like.
Safety Car
Joined: Aug 2000
Posts: 3,711
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From: San Antonio TX
The base-engined '72 is exactly the same engine that was used in '71 and is the result from the '70 350/300. The compression dropped in '71, which resulted in the 30hp gross rating loss from '70 to '71. There is absolutely no difference between a '71 350/270 and a '72 350/200 engine...not one bit other than the change in the SAE rating specification. You can't go by the sales brochure information since they are notoriously inaccurate. If they were accurate, the '68 Vette's t-tops would have been a one piece true targa (which is what the "T" in the t-tops means) and the LT-1 would have been installed in the '69 Vette.